Change: Use dev group instead of dev dependencies for poetry

dev-dependencies got replaced by using generic groups. Requries poetry
>= 1.2.0.

pyproject.toml

@@ -34,7 +34,7 @@ lxml = ">=4.5.0"
 defusedxml = ">=0.6"
 
 
-[tool.poetry.dev-dependencies]
+[tool.poetry.group.dev.dependencies]
 coverage = ">=7.2"
 pylint = ">=2.17"
 sphinx = ">=5.3.0"